The effect of heat waves on mental health in a temperate Australian city.
OBJECTIVE
The goal of this study was to identify mental, behavioral, and cognitive disorders that may be triggered or exacerbated during heat waves, predisposing individuals to heat-related morbidity and mortality.


METHODS
Using health outcome data from Adelaide, South Australia, for 1993-2006, we estimated the effect of heat waves on hospital admissions and mortalities attributed to mental, behavioral, and cognitive disorders. We analyzed data using Poisson regression accounting for overdispersion and controlling for season and long-term trend, and we performed threshold analysis using hockey stick regression.


RESULTS
Above a threshold of 26.7 degrees C, we observed a positive association between ambient temperature and hospital admissions for mental and behavioral disorders. Compared with non-heat-wave periods, hospital admissions increased by 7.3% during heat waves. Specific illnesses for which admissions increased included organic illnesses, including symptomatic mental disorders; dementia; mood (affective) disorders; neurotic, stress related, and somatoform disorders; disorders of psychological development; and senility. Mortalities attributed to mental and behavioral disorders increased during heat waves in the 65- to 74-year age group and in persons with schizophrenia, schizotypal, and delusional disorders. Dementia deaths increased in those up to 65 years of age.


CONCLUSIONS
Our results suggest that episodes of extreme heat pose a salient risk to the health and well-being of the mentally ill.


CONCLUSIONS
Improvements in the management and care of the mentally ill need to be addressed to avoid an increase in psychiatric morbidity and mortality as heat waves become more frequent.
Hansen
Alana
A
Discipline of Public Health, School of Population Health and Clinical Practice, Faculty of Health Sciences, The University of Adelaide, Adelaide, South Australia, Australia.
Bi
Peng
P
Nitschke
Monika
M
Ryan
Philip
P
Pisaniello
Dino
D
Tucker
Graeme
G
D006358:Hot Temperature; D006801:Humans; D001523:Mental Disorders / Q000453:epidemiology / Q000209:etiology; D008603:Mental Health; D010343:Patient Admission / Q000706:statistics & numerical data; D013021:South Australia / Q000453:epidemiology